The present invention relates to a semiconductor device, and more particularly to an integrated semiconductor circuit device wherein a wiring conductor layer crosses over or under a semiconductor resistor region.
Resistors formed within an integrated semiconductor circuit device are constituted by, for example, a semiconductor region of one conductivity type formed in a semiconductor substrate. Their resistance values are determined by the sheet resistance, width, and length of the respective semiconductor regions. In addition to the resistors, the integrated semiconductor circuit device has a large number of other circuit elements such as transistors, diodes and capacitors. Wiring conductor layers are used for interconnecting the respective circuit elements. The wiring conductor layers are formed over an insulation film covering the semiconductor substrate. The wiring layers are connected through contact holes formed in the insulation film to elements in the substrate.
Some of the wiring conductor layers often cross over the resistor region. The wiring conductor and the resistor region are isolated from each other by the insulation film. However, at the intersecting section, the construction is conductor-insulator-semiconductor. This construction is the same as that of a MIS (metal-insulator-semiconductor) capacitor. In other words, the resistor region and the wiring conductor layer are capacitance-coupled to each other at the intersecting portion. For this reason, a part of the signal at the wiring conductor layer may be transmitted to the resistor region due to the capacitance-coupling. Conversely, a part of the signal current flowing through the resistor region may leak into the wiring conductor. Signal transmissions due to the capacitance-coupling cause crosstalk, parasitic oscillation, maloperation, etc.
The capacitance-coupling can be suppressed by thickening the insulation film in the intersection area which exists between the resistor region and the wiring conductor layer. However, an increase in the thickness of the insulation film on the resistor region inevitably increases the thickness of the insulation layers on other circuit elements. As a result, the depths of the contact holes increase, and wiring conductor layers extending from the contact holes and over the insulation layer may be open-circuited at the edge of the contact holes. Furthermore, the patterning of fine wiring conductor layers becomes difficult.